The present invention(s) relates to a structure and method for improved auxiliary thruster systems for marine and small vessels, including small fishing and pontoon boats. Particularly, the invention(s) relates to auxiliary thrusting and maneuvering systems that protract and retract a trolling motor assembly and can be used in marine vehicles in addition to, or independently of, the main propulsion of the vehicle or watercraft.
Trolling motors are well known in the art and have been used for many years, particularly for small watercraft such as fishing boats and recreational vessels. Such a small watercraft is often lightweight and generally has a main outboard motor mounted to the boat's transom. The main motor performs as the boat's main thruster and propulsion system. Due to the lightweight nature, this small watercraft is regularly subject to being tossed about in rough waters or set adrift in strong currents, strong winds, or after a race boat speeds by, leaving choppy water or a high wake. Often, it is undesirable to employ the main outboard motor. For instance, in strong wind or rough waters it may be impracticable to employ the main drive of the vessel because it may provide more thrust and motility than needed and may not be fuel-efficient for such purposes. While traveling close to the shoreline, the main outboard motor is undesirable in some instances as it may cause unwanted waves that may frighten away fish, damage the shoreline, or pose a danger to other boaters or swimmers. Another danger of using the main outboard motor while close to the shoreline is the possibility that debris may impact the motor or become lodged into the motor.
The single thruster propulsion system also poses problems when attempting to dock watercraft. In order to dock a vessel, the vessel must be pulled up alongside the pier, slowed to a pace that will allow the driver or deckhand to grab hold of the pier either physically or by rope, sufficiently latched to the pier, and then stopped from drifting further once latched to the pier. One solution to the difficulty of docking the watercraft is that the captain, or driver, of the vessel often must employ a second person to assist them in docking the vessel as they direct and maneuver the vessel from a rear mounted main thruster. Without a second person, the driver of the vessel must steer the vessel as well as pull the vessel to the pier with a rope.
To solve these problems, those skilled in the art have long attempted to employ auxiliary propulsion systems for steering and maneuvering light-to-medium watercraft. The most problematic result of the addition of a fixed, auxiliary thruster is that the auxiliary thruster would provide drag, slowing the vessel, and add an extra element which may collect debris as the vessel travels. Additionally, for small watercraft the addition of an additional auxiliary thruster may make transferring the vessel to and from the water difficult, as the auxiliary thruster may be damaged when being pulled from the slip, or the maneuvering involved in preventing such damage would be all too unwanted. For these reasons and others, the addition of retractable or semi-retractable auxiliary thrusters have been utilized in the marine industry for many years. The known art relating to retractable auxiliary propulsion systems include two types: systems for larger marine vessels, often called a bow thruster in the known art, and the utilization of trolling motor systems utilized by smaller recreational fishing boats. The retractable propulsion systems for larger vessels employ a system for which the thruster is lowered and retracted through a compartment of the hull of the vessel. These systems are only available for larger vessels with sufficient space between the bilge of the ship and the top deck to house such an auxiliary thruster system and compartment that could be flooded upon deployment of the auxiliary thruster. These systems are unavailable to small watercraft because there is insufficient space for such a compartment.
To overcome these obstacles for small watercraft, the trolling motor has been known to the art for many years. There have been several different trolling systems used for small watercraft, all of which attempt to solve the problems discussed above. The mere number of different systems shows the industry efforts in creating a system that is easy to use and solves most of the problems previously discussed. Early in the art, some attempted to solve the problems inherent with the maneuverability of small watercraft through the use of a trolling motor mounted to the boat's transom (for example, U.S. Pat. Nos. 2,744,418 and 3,139,853).
The known art has since evolved and at present, most auxiliary propulsion systems for smaller fishing vessels are retractable and mounted on the deck of the vessel in a forward position near the bow. The thruster, usually a trolling motor, must manually be lowered into the water for operation and use of the thruster assembly, which often contains an extension arm mounted to a folding bracket employed to conserve space when in the retracted position when the vessel is being propelled at normal speeds by the main propulsion system. These systems require the driver of the vessel to leave his position at the helm to place the motor in and out of service and to control the speed and direction of propulsion. Previous incarnations of this system also required the manual adjustment of the position of the motor. Other problems that arise from the deck-mounted, bow thruster assembly design include the necessary use of valuable deck space for an idle auxiliary motor. While not being employed, the motor usually stays on the deck of the vessel and often becomes a hazard on the deck, severely restricting the personnel movement on the deck. Some systems are mounted to the bow of the vessel similarly to the mounting of the main outboard thruster located on the transom of the boat. These systems are bulky, obscure the captain's vision while navigating the vessel, and are often required to be manually deployed for service and manually steered.
Others skilled in the art have attempted to solve this problem for smaller watercraft by suggesting the use of a retractable docking line coupled to a rotatable spool used to pull the vessel to the shore or pier. This may solve the problem of docking the watercraft, but this posed solution does not address the issues of maneuverability inherent in the small watercraft construction.
As the above-referenced scenarios exhibit, a secondary thrusting system, such as is known in the art, is nearly a necessity for small watercraft, and although many auxiliary thruster systems are known to the art, all, or almost all of them suffer from one or more disadvantage. Therefore, there is a need to provide an improved design and apparatus for auxiliary thruster systems for marine vessels.